Machine tool



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Dec. 3, 1940. w. F. RIDGWAY MACHINE TOOL Filed April 15, 1959 7 Sheets-Sheet 2 u!!lwmuwmlllllll NVELNTOQ/ @//7//70/77 S/Q/b/gw ai Coni-4H, 7

CTTOmEg/s Dec. 3, 1940.

W. F. RIDGWAY MACHINE TOOL Filed April 15, 1939 FSA,

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'7 Sheets-Sheet 3 FASTER SLUWER G) I'COMMUNI '-AUXILLIARY-l NVENTOQ,

nowrap@ De@ 3 1940- w. F. RIDGWAY 2,224,108

MACHINE TOOL Dec. 3, 1940. w. F. RIDGWAY 2,224,108

MACHINE TOOL Filed April l5, 1959 '7 Sheets-Sheet 5 (DBC Def 39 E940 .Y W. F. RlDGwAY 2,224,108

MACHINE TOOL Filed April 15, 1959 v sheets-sheet s Dec. 3, 1940.

W. F. RIDGWAY MACHINE TOOL Filed April l5, 1939 7 Sheets-Sheet 7 64 of.; Lp i j W, (jITTOmixf-.ys

Patented Dec. 43, 194@ mamma Toor.

William F. Ridgway, Rockford, lill., assignor to The Ingersoll Milling Machine Company, Rockford, Ill., a corporation of Illinois Application April 15, i939, .seriai No. :esatti 26 claims.

The present invention relates to machine tools and particularly to the control of power drives therefor. y

The generalobject is to reduce the number of manual control devices that are required for full andneffectual control of the many different functions capable of being performed by a multiple drive machine tool.

A more speclc objectof the invention is to l0 provide a machine tool embodying a plurality of drive mechanisms and a novel means for selectively placing different ones of the mechanisms in control of a setn of manually operable control devices.

A further object is to provide a manual set of control devices for eifecting complete control of a selected machine tool element and an auxiliary set of control devices adapted to eiiect partial control ,of a diierent one of the machine tool elements.

Still another object is to utilize a common selector mechanism ior associating the main and auxiliary controls with different machine elements.

Another object is to provide a novel arrangement of control devices which enables the motion of a machine tool element to be arrested by a device which normally controls a different function.

A further object is to provide a machine tool havingva plurality of movable. elements adapted to be locked or clamped against accidental displacement together with a novel control arrangement for selectively governing the application and l release of the dlierent clamps.

Still another object is' to provide for applicas tion of one of the clamps by one control device and release of such clamp by an independently operable device which initiates movement of the clamp element andthereafter initiates movement of the clamped element, such movement being initiated immediately in the event that the clamp fis released when the second control device is actuated.

The invention also resides in the novel manner of grouping the manual control devices and in selectively associating the same with different machine elements.

. Further objects and advantages of the invention will become apparent as the following description proceeds taken in connection with the accompanying drawings, in which Figure- 1 is a fragmentary end elevation of a machine tool embodying the invention.

Fig is a front elevation of one of the machine element clamping mechanisms included in the machine tool of Fig. 1. v

Fig. 3 is a view, partially in longitudinal vertical section, of a portion of the clamping mechanism of Fig. 2.

Fig. 4 is a transverse vertical sectional view along the line @-4 in Fig. 2.

Fig. 5 is a detailed sectional view along the line 5 5 in Fig. 4.

Fig. 6 is a front elevation of the control pendant for the machine tool of Fig. 1.

Figs. 7 and 8 are wiring diagrams of the low voltage control circuits.

Fig. 9 is a wirlngdiagram of the intermediate or secondary control circuits for the feed motors. 1.5

Fig. l0 is a wiring diagram of the rheostat adjusting motor control circuits.

Fig. 1l is a wiring diagrampf spindle and feed motor energizing circuits.

Fig. 12 is a wiring diagram of the intermediate or secondary control circuits for the rapid traverse, clamp and pump motors.-

Fig. -13 is a wiring diagram of the energizing circuits for rapid traverse, clamp and pump motors. y 25 For purposes of illustration of its various novel features, the invention has been shown herein as embodied in a horizontal-spindle traveling-column open side milling machine, but it will be understood that the invention is also applicable to a wide variety of other types of machine tools.

claims. are intended to cover all modications'35 and 'alternative constructions falling within the spirit and scope of the invention.

GENERAL MACHINE STRUCTURE The milling machine selected for purposes of illustrating the invention is typical of those ma- 40 chine tools in'which the cutter and the work piece may be fed relative to each other in opposite directions along a plurality,l three in this instance, of paths each extending at right angles 45 to each other or, by a combination of movements along two of these paths, may be fed along a resultant angular path. The machine, the major elements of which are shown in Fig. 1, comprises an elongated horizontal Work table Il) stationarily mountedon a suitable bed Il. Overhanging the work table l0 is a rotatable milling cutter or metal removing tool I2 carried by a spindle I3, which is journaled within a ram `I4 supported by and shiftable axially relative to a saddle l5.

Vertical adjustment of the cutter I2 is accomplished by traversing the saddle along vertical ways I6 fashioned on a column or housing I1. Similarly, movement of the cutter I2 longitudinally of the table' I9 is accomplished by traversing'the housing I1 along horizontal ways I6 on themachine bed II.

Rotation of the cutter and feeding or rapid traversing thereof in opposite directions in the three dimensions is effected by three main power driven mechanisms or power packs, designated generally by the letters A, B, and C, and included in the illustrative machine. The power pack A includes a single reversible variable-speed electric motor I9 adapted to rotate the tool spindle I3. 'I'his motor is connected to the spindle through suitable gearing 29 with the final driven gear splined on the spindle I3 to permit axial movement of the latter.

The second or B power pack is adapted to be connected alternatively to one or the other of Iz'wo machine tool elements, shown herein as the saddle I5 and the ram I4. Accordingly, this single power pack can be used at willeither to raise and lower the saddle I5 or to project and retract the ram I4. The power pack itself includes a feed motor 2I and a rapid traverse motor 22 connected respectively to terminal elements 23 and 24 of a differential gearing 25. The intermediate or driven element 26 of this differential gearing drives a horizontal power take-off shaft 21V which is in turn connected through bevel gears 28 with a vertical shaft 29. The power pack B and the shafts 21 and 29 are all mounted on the transversible column I1.

To connect the power pack B with the ram I4. a clutch 89 is provided having a driving member 8| connected by bevel gears 62 with the shaft 28 and an axially shiftable driven member 88 splined on a shaft 34. This shaft 8,4 is connected through gears 35 with a screw 86 threaded within a traveling nut 61 fixed on the ram I4. Consequently, when the clutch 89 is engaged, the power pack B rotates the lead screw 86 and projects or retracts the ram -`I4. In a similar manner, the power pack B is alsol connectible with the'saddle I5 through a second, and alternatively closa-ble clutch 68. 'I'his clutch 88 includes a driving member 89 connectedto the shaft 29 through bevel gears 49 and an axially shiftable driven member 4I-splined on `a shaft 42., 'I'he shaft 42 is in turn connected through two sets of bevel gears 48 with a pair of vertical lead screws 44 threaded within traveling nuts.

45 fixed on the saddle I5. Accordingly, upon 'rotation of the lead screws 4.4, the saddle I5 is traversed up or down along the verticaLways I6 on the housing I1.

Alternative engagement of one or the other of the clutches 99 and 88 is accomplished by means of a rockshaft 46. This is connected to 4est the axially shiftable drivenv member 4I of the y clutch 48 by rcker arm-41 fixed on the rockshaft. Similarly, -the-rockshaft 46 is also connected by a rocker arm 48 splined on the lower portion of the shaft with the axially shiftable driven member 33 of the other.clutch 39. The rockshaft 46 is oscillated in a clockwise direction (as viewed from its upper end) by a solenoid SS to engage the clutch 88 and thereby connect the power pack B with 4the saddle I5. Similarly, the rockshaft 46 is oscillated in the opposite direction by a solenoid SR to disconnectv the clutch 38Hand engage the other clutch 39 so that the, power pack B is connected to the ram I4.

The third or C power pack is similar to the B power pack in that it also includes a feed motor 49 and a rapid traverse motor 59 connected to respective terminal elements 5I and 52 of a differential gearing 53. In this case, however, the intermediate or driven element 54 of the planetary gearing operates through a shaft 55 and a suitable gearing 56. This mechanism meshes with a partial nut 6I xed to the under side of the column I1. supplied from a suitable pump (not shown) driven by a pump motor 62 (Fig. 13). In each of the B and C power packs, a brake (not shown)y is utilized for holding the rapid traverse motor against rotation when idle, the brake being automatically released whenever the associated motor is energized.

MACHINE ELEMENT HOLDING Daviess 68, 69, and 19. In the case of the column clamp 65, the -motor 68 shifts axially movable plungers 1 I to move the clamping jaws 12 into and out of clamping engagement with the undersides of the ways I8. Similarly, in the saddle clamp 66, the motor 69 actuates plungers 13 to move jaws 14 into and out of clamping engagement with the inner side of the ways I6 while in the ram clamp 61, the motor 19 actuates a plunger 15 and a lever 16 and shifts a shoe 11 on the lever into and out of clamping engagement with the ram periphery. i

'I'he various clamps are all substantially identical in construction and accordingly, a detailed description of the column clamp will suffice for all. I'he motor 68 (see Fig. 2) is mounted in the center of an elongated tubular housing 18. It may conveniently be energized with three phase alternating current and includes an armature 19 (Fig. 3) and a stator 89 which forms the central portion of the housing 18. Projecting from each end of the rotor 19 are threaded shafts 8 I having right and left hand screw threads thereon and which are journaled for rotation within the housingl 18. Arranged in spaced relation, and threaded on each of the shafts 6I, is a pair of blocks 8. and 83 held against rotation within the housing 16 so that they are traversed along the shafts 8i upon the `rotation of the latter and serve to actuate the clamping plungers 1I in the manner described below.

To'form a lost motion connection between the fspaced blocks 62-83 on the shafts 8i and the plungers 1 I, sleeves 84 are slidably mounted within the housing 18 between each pair of the blocks. These lsleeves are shifted axially inwardly to clamp the jaws 12 and outwardly to unclamp the same. `'Ihe blocks 82 are arranged in spaced relation to the ends of the sleeves 84 to provide a lost motion connection therebetween, however, so

that) the motor 68 will have an opportunity to accelerate before one or the other of the blocks 82--83 contacts the sleeves 84. When the blocks 82-83 do contact the sleeves 84, they strike them with a sharp hammer-like blow so that full actuation of the clamps is positively assured. Helical springs 8|"l form yieldable stops for the blocks Lubricant for the gearing is ing with gears 8l (Figs. 3 and 4).

ings 88 (Fig. 4) within a cylindrical housing 89.

The gears 81 are not, however, fast on the plung.- ers Vl but are connected thereto by loose spline couplings formed in each case by internal gear teeth 90 formed in a bore in the lower end of the gear t1 and meshing with external gearV teeth Sl on a sleeve 92 located within the gear 31. This sleeve is in turn journaled in ball bearings 93 within the housing 89 and is threaded on the upper end of the plungers il. These plungers are held against rotation by keys 9B so that when the sleeve v92 is'rotated by the gear si? meshing with the rack sleeve 84, the sleeve acts as a traveling nut and shifts the plungers 'il axially. in the particular arrangement shown, the blocks t2 drive the rack sleeves 84 inward in a direction to move the plungers il upward into clamping position and similarly, the blocks 93 drive the rack sleeves 84 in an opposite direction to shift the plunger lli downward into unclamping position. It should be noted that the sleeves or traveling nuts 92 rest with their lower ends on ball bearing type thrust bearings 93 so that all thrust incident to the clamping operation is taken up at this bearing.

To deenergize the clamping motor S8 at the termination of the clamping and unclam'ping operations, limit switches |2LS and MLS (Fig. 5) are urged toward open position by spring actuated plungers 99 and |00. The switch MLS also embodies a second set of interlock contacts I2LSA (Fig. 8) arranged to close only when contacts I 2LS open and thereby prevent operation of the C power pack to drive the housing ll' except when the latter is unclamped. The plunger IUI) is depressed by the rack sleeve 84 when the latter is in its clamping position and similarly, the plunger 99 is depressed by the opposite end of the .latch sleeve when the latter is in its unclamping position. It should be noted here that in the saddle and ram clamps 66 and Si respectively, similar pairs of limit switches @LS- MLS and ILS-SLS are also provided (Fig. il), and the switches @LS and illLS include additional interlock contacts BLSA and HULSA (Fig. 8) for preventing operation of the B power packto drive the saddle or ram exceptwhen the corresponding element is unclamped.

The saddle clamping mechanism til is intended primarily for use during boring operations when extreme rigidity of the saddle i5 is required. When the machine tool is being used for ordinary milling operations, however, there is some possibility of the saddle i5 settling if the clamp BS is not active, since the lead of the threads on the screws B4 is frequently rather large. To overcome this dlculty, a supplemental brake mechanism I0! (Fig. 1) ls utilized fourl holding one o the lead screws 44 against rotation whenever the saddle l5 is stationary. 'I'his brake mechanism may be of any well known form and has been shown as including a, brake drum i02 engageable by a friction shoe |03 normally urged into engaged position and actuatable into brake released posi-` tion by a solenoid SB. Through the medium of the control circuits hereinafter described, the

solenoid SB is automatically energized to release the brake it whenever the lead screw i4 is being driven to traverse the saddle l5.

MANUAL CONTROL DEVICES Control of all three of the power packs A, B, and C to start, stop, and determine the direction of movementof the machine element actuated thereby, in this instance the cutter, is accomplished by a set of manually operable control devices, preferably in the form of switches, grouped together and carried by a panel or pendant t3 (Figs. l and 6) which is readily movable about the machine tool so as to permit all of the various functions to be governed selectively from a point remote from the power mechanisms. The panel t@ comprises a relatively small and elongated boxlike casing which, as shown in Figs.'l 6 and '7, houses the control switches and supports their exposed actuating members. The electrical connections between these switches and the power pack controllers are extended from the pendant casing through a flexible cable of such length as to enable the pendant to be moved conveniently to anygdesired position about the work table i0. Rigid bars A i@'fi along the vertical sides of the pendant casing deiine nger openings so that the operator may both support the pendant and operate the various controFdevices with one hand only. The control devices are of the single or multiple switch type and have movable actuating members in the form of push buttons,. levers, or the like projecting through or disposed on the face of the pendant casing.

The present invention contemplates a novel arrangement of the control devices and association thereof in a novel manner with the controllers for the power actuators so that a relatively large number of operating functions of the machine tool, performed singly or in combination, may be controlled by manipulation of a comparatively smaller number of control devices which may be operated quickly and conveniently and without danger of confusion. As a result, the machine tool may be controlled from a selected remote point rapidly, precisely, and efciently with a substantial reduction in operating time required to machine a given work piece.

Generally stated, two factors contribute largely to this substantial reduction in the number of control switches. First, is the use of a selector or selectors to connect a 4group of the control switches with a selected one of the drive mechanisms rather than duplicating the group for each drive mechanism. Second, is the utilization of the individual switches to perform a plurality of different controlling functions.

To facilitate their quick location and comprehension of their function by the operator, the

'control devices or switches are arranged on the any one of (a) the ram I4, (b) the saddle l5, or H (c) the column il. By using this single set of main switches to control any selected one of several drive mechanisms, duplication of switches lfor each drive mechanism is obviated. On the otherhand, in certain'machining operations such the saddle I5 vertically with respect to the table..

To permit this type of machining, a set of controls designated as the auxiliary -group is arf ranged to be connected to selected ones of the drive mechanisms. In particular, the selector switch |05 can be shifted to either its ra.m, verticai, or horizontal" positions in which it places the main" set of switch actuating members in control of the movements of the ram I4.

'the saddle I5, and the housing I'l respectively.

At the same time, the selector |05 automatically adapts the "auxiliary" set of switch actuating members for control of the drive mechanism for traversing the column I1 when lthe selector |05 is in its ram" or` vertical positions and adapts the auxiliary controls for controlling the movements of the saddle I5 when the selector is in its horizontal" position. In other words, conditioning of the selector |05 to place a selected one of the movable machine elements under the control of the main control devices automatically places within the control of the auxiliary" devices a predetermined machine element the actuation o'f which produces a movement at right angles to that of the machine element then under control of the main devices. Finally, a

common group of switches is arranged to be connected selectively to any one of the drive mechanisms including not only those selected for control by the main or auxiliary groups but also to the spindle drive mechanisms.

Considering first the several selection functions performed by the selector switch |05, this serves, when in its respective ram and vertical positions, to energize the respective clutch actuating solenoids S'R and SS (Fig. 1) to connect the B power pack to traverse the ram Il and the saddle I5 respectively. Second, it connects the main group of switches to the B power pack when in its ram and vertical positions, and connects this set of switches to the C power pack when in its horizontal position. In other words, it places the main group of control switches in command of any selected one of the three movable machine tool elements, namely, the ram Il, the saddle I6, and the housing I1, and additionally, it determines which of the two elements Il and I5 shall be connected to the B power pack since this power pack is used alternatively for one or the other. Third, the selector switch |05 connects the "auxiliary set of control switches to a non-selected one of the drive mechanisms. As was previously noted. it connects the auxiliary set of controls to the C power pack for the housing I1 except when the main set of controls is connected to this power pack and in the latter event, the selector connects the auxiliary set of controls to the B. power pack and also connects this latter power pack to the saddle I5`- Fourth, the selector switch y |05 connects a single lock control device ||0 on the pendant 03 with any desired 'one of the clamps 66--01 for the column, saddle, and ram respectively. This loc control device is, in fact, part of the main" group of switches, but

- the selector |05 can be shifted to the proper one of its three positions and the clamp mechanism operated without setting in operation the drive mechanism kfor the corresponding element of the machine.

Briefly stated, the functions of the switches in the several groups on the pendant 63 (Fig. 6) are as follows:

Spind1e" group The run push button switch |00 starts the spindle motor I9 whenthe push button is even momentarily depressed. Second, when the "run" push button is held down. it connects the faster" and slower push button switches |01 and Ill of the common" group with the speed adjustment mechanism of the spindle motor I0.

` The jog push button switch |00 stops not only thespindle motor Il but also all of the other drive motors in the machine tool as soon as it is depressed so that it acts as an emergency stop control device for the entire machine. Additionally, if the "jog" push button |00 is held depressed, it acts as a hold-down -Jog switch and causes the spindle motor I0 to rotate the tool spindle Il at a low jog speed for adjusting the angular position of the cutter I2.

The rotation switch III is of the toggle type and has a two position movable element which determines the direction of spindle rotation.'

Furthermore, it may be used as a spindle motor stop switch since it will stop the motor I9 whenever it is shifted fromone position to the other while the motor is running, reactuation of the "run switch |08 being required to restart the motor in the new direction.

"Main group i the feed motors 2| or 49 with which the run" switch is associated at the time.

The "jog push button switch |I2 serves, when momentarily depressed, to stop the feed motor in the particular one of the power packs B or C that may at any time be in control of the main group of switches. Secondly, if the jog" switch |I2 is held depressed, it acts as a hold-down jog switch and causes the associated feed motor 2| or 49 to operate at a slow jogging speed for adjusting the positionof the associated machine tool element.

The Ftravrse switch IIS is a hold-down switch for maintaining in operation, during tle time it is held depressed, the rapid traverse motor 22 or 50 of one or the other of the power packs B and C to which the mainf set of controls is connected by the selector |05.

The fast feed push button switch ||4 is a hold-down switch and serves, when held depressed, to connect the associated one of the feed motors 2| and I8 for traversing the associated machine tool element at a fast feed rate intermediate the rapid traverse and normal feed rates. y

The "direction selector switch IIB is of the toggle type with a two position movable element and acts to determine the direction of rotation of both the feed and rapid traverse motors in the associated one of the power packs B and C. Additionally, if the selector switch M5 is shifted from one position to the other while the associated power pack is in operation, it will stop the feed motor in the power pack which may have been running and it can only be restarted by reactuating the run button The lock push button switch ||6 is operable upon a momentary actuation thereof to energize any one of the clamp motors (S8-ill selected by the selector switch |05, to move the associated clamping mechanism vinto clamped position. It should be noted here that upon restarting of the drive mechanism for the clamped machine element, the clamping mechanism is automatically released before the drive mechanism actually starts to operate.

Auxiliary group The profile push button switch ||l| starts the feed motor of the power pack B orv C to which the auxiliary set of controls is connected. Furthermore, this switch maintains such feed motor in operation only so long as the switch is held depressed and automatically stops the feed motor when the switch is released. A latch illa is provided on the pendant adjacent the button lll and, when shifted upwardly while the button is depressed, serves to hold down the button ||1 for sustained operation of the feed motor which it controls. In addition, the profile switch ||6 also conditions the faster" and slowerfi push buttons |'l and |08 of the common group to adjust the speed of the feed motor controlled by the profile switch when the latter is held depressed.

The "direction selector switch M8 is of the toggle type and has a two position movable element which determines by 'its setting the direction of rotation of the feed motor to which the jauxiliary -set of controls is connected. Furthermore, shifting of the selector switch M8 from one of its positions to the other while the associated feed motor is in operation serves to stop the same.

Common group The faster and slower push button switches |01 and |08 are alternatively available for speeding up or slowing downv either of the feed motors 2| and 49 or the spindle driving motor i9. As was heretofore noted, the particular motor which they are effective to control depends upon the selection function of the run push buttons |06 and and prole button lil. The speed changing operation takes place so long as one or the other of the faster or "slower buttons is held down.

Of the above switches on the pendant $3, the push button switches are all spring biased to open position. IThe selector switches |05, M0, M5, and. i 8 are, on the other hand, all position-maintaining switches, that is, the movable actuating element is retained by yieldable detent action in any position to which it is shifted manually and the movements of the movable switch contacts from position to position occur with a snap action in response to shifting of the actuating element.

' The switches |'|0, ||5 and ||8 are of the standard toggle type. 'Ihe'switch |05 is also of well known construction, one form being manufactured by the Cutler Hammer Company and identied as No. 7012.

' GENERAL CIRCUIT ARBANGEMENT Suitable supply lines are provided for the various parts of the electrical control and motor energizing systems. High voltage alternating current of, say, 220 volts is furnished by three phase supply lines Li-Lz-Lg (Fig. 13) for the rapid traverse motors 22 and 50 as well as for the clamp motors 68-l0 and the lubricant pump motor 62. Single phase alternating current may be utilized from a pair of these supply lines Li-La for the rapid traverse, clamp, and pump motor `contactors (Fig. l2) as well as for the clutch solenoids SS and SR and the brake-solenoid SB. Since the spindle and feed motors |9, 2|, and 49 are all variable speed motors, they may more conveniently be direct current motors rather than alternating current and are accordingly supplied from high voltage direct current supply lines L4L5 at, The rheostat adjusting motors associated with the spindle and feed motors (Fig. l0) as well as the feed motor contactors and intermediate control relays (Fig. 9) may also be conveniently energized from the same direct current supply lines Lt-Ls. 'Io minimize the size of the manual switches and the conductor insulation required, however, the switches on the pendant 63 are preferably included in low voltage control circuits supplied, for example, with alternating current at twentyfour volts by supply lines Le-L'i (Fig. 7)

For the sake of simplicity of analysis, line-toline wiring diagrams have been used (Figs. 7 to 13) and the networks of different voltages have been shown separately. Since the network of Fig. 8 is connected between supply lines Ils-Ls, which also appear at the bottom of Fig. 7, these two wiring diagrams in Figs. 7 and 8 may be placed end to end with Fig. 8 below to form the complete low voltage control network. Similarly, the direct current networks of Figs. 9, 10, and 11 may all be considered as a unit since all connections are between the same pair of supply lines Iii-L5. In the same manner, the networks of Figs. 12 and 13 may be considered together since that of Fig. 12 constitutes connections between two of the three supply lines included in the three phase system of Fig. 13.

The feed motors 2l and 49 for the B and C power packs, as well as the spindle motor |9 of the A power rack, are all reversible adjustable speed motors and have been shown (Fig. l1) as being compound direct current motors. In particular, the spindle motor |19 has an armature i I9, a shunt eld |20, and a series field |2|. Sinnlarly, the feed motors 2| and 49 have respectively armatures |22 and |25, shunt elds |23 and |26, and series fields |2| and |27.

Speed variations for the feed motors 2| and 40 as well as the spindle motor i9 are accomplished by varying their shunt field excitations through the medium of rheostats |28, |29, and |30 respectively (Fig. 11). rIl he setting of these rheostats is in each case varied by an associated reversible rheostat adjusting motor i3 i, |32, and |33 respectively (Fig. Each of the rheostat adjusting motors includes a respective armature i3d-|36 and apair of alternatively energizable field windings il-MZ for driving the motor in correspondingly opposite directions to change the setting of the driven rheostat commensurately. In

particular, when the rheostat adjusting ir'notor fields |311, |39, and ilii are energized. the rheo-fv stats are shifted to increase the speed of the motors which they control, and conversely, when the rheostat adjusting motor fields |38, |40, and M2 are energized, the rheotats are shifted to decrease the speeds of the associated motors. The usual limit switches are provided for preventing overtravel of the rheostat adjusting motors I 3I-I 33. Thus, the motor I3I is stopped at the respective limits of its travel by opening of one or the other of the limit switches I3LS or I4LS, and the motors |22 and |33 are similarly stopped by correspondingsets of limit switches ISLS-IBLS and NLS-ISLE. l

To minimize the shunt ileld heating while the spindle and feed motors are idle, economy resistors lli-| are inserted in series with the shunt field windings |20, |22 and |22, respectively (Fig. 11) These shunt fields are connected across the supply lines Li-Ls at all times. Accordingly, the resistors lli-ill serve to cut down the eld current when the motors are idle. Whenever one of these motors is running, its economy resistor is automatically shunted Vout of the field circuit.

Also associated with the spindle and feed motors (Fig. 11) are the usual starting resistors I i in series with the motor amature, and

dynamic braking resistors I IS-IBI in shunt with the armatures.- Cutting of these resistors into and out of circuit for proper starting and stopping is accomplished by suitable control relays as hereinafter described.

The rapid traverse motors 22 and 5l of the power packs B and C, respectively. the clamp motors l-lll, and the lubricant pump motor 62 have all been shown as conventional constant speed three-phase alternating current motors (see Fig. 13) These motors are reversed by changing the order of the phase connections of their windings in the usual manner through the medium of suitable reversing contactors..

In the control circuits, the manually operable control switches on the pendant 63 (Fig. 6) are connected through low voltage conductors leading through the eirible conduit 64 to a group of etc.

low voltage control relays in the low voltage control network (Fig. 1), viz: control relays ICR. to IBCR inclusive, a spindle jog control relay JS, a spindle run relay CRR, spindle direction control relays FS and BS energizable respectively for forward and backward rotation of the spindle, a spindle overload relay Ol, and a spindle motor circuit maintaining relay RS. Also included in the low voltage network (Fig. 8) is a set of primary control relays for the feed motor 2| of the B power pack including a fast feed relay FFB, a jog relay JB, a run relay RB, and forward and backward reversing yrelays FB and BB. Further,

in this low voltage control network is a similar set of primary control relays forthe feed motor 49 of the C power pack' including a fast feed relay FEC, a jog relay JC,l a run relay RC, andv forward and backward reversing relays FC andV BC. Finally, the low voltage network includes a lubricating pump motor control relay LP and an associated time delay'relay 'I'D for governing the energization of the lubricant pump motor B2.

From the foregoing it will be seen that the designation symbols for the various low voltage relays indicate to some extent the apparatus with which they are associated and the funuctions performed. The same style of symbols has been used for the other relays and contactors in the remaining control networks described below. In, each case, the contacts or switches actuated by each relay are designated by the same symbol using succeeding numbers to indicate, the particu-` lar set of contacts. For example, the sets of contacts for the control relay ICR 4are ICRI, I CR2,

'I'he feed motor 2| of the B power pack is controlled through the mediumof a set of secondary relays or contactors (Fig. 9) including: an acceleratingrelay FAB, a, time delay relay IIB for controlling the starting resistance |41 and including main and neutralizing windings IIBM and IIBN, a starting resistance controlling relay IAB controlled by the time delay relay IIB, direction controlling contactors IFB and 2FB for forward rotation and IRB and 2RB for reverse `rotation, a dynamic braking relay DBB, and a field decelerating relay FDB, the current coils for the accelerating relay FAB and decelerating relay FDB as well as the actuating, winding for an overload relay OLB being shown in Fig. 11. A non-plugging relay PLB (Fig. 11) is also provided. A similar set of secondary control relays mediate relays described above, the current windings for the. accelerating and decelerating relays FDC and FAC. as well as an overload relay OLC are shown in Fig. ll.

For the spindle motor I8 a set of secondary control relays or contactors (Fig. l0) is provided. including time delay starting relays IIS and I2S having respectively main and neutralizing windcontactors IFS and 2FS for forward rotation and IRS and 2RS for reverse rotation, and a dynamic braking relay DBS. An overload relay OLS and a non-plugging relay PLS for the spindle motor are shown in Fig. ll.

The rapid traverse motors 22 and 50 of the B and C power packs, respectively, are controlled by corresponding sets of secondary reversing contactors RAB--RRB and RAC- RRG (Fig. 2). The ram clamping motor 'III is connected for clamping and unclamping movement respectively by reversing contactors RL and RU. Similarly, the housing and saddle clamping motors 88 and 69 are controlled for clamping and unclamping movement by corresponding sets of reversing contactors HL and HU and VL and VU. Also, associated with each of the group of three-phase motors 22, 50, 02 and 68-10 shown in Fig. 13 are corresponding overload relays OLRB, OLRC, OLLP, HOL, VOL and ROL, respectively, which are actuated to open their normally closed contacts in response to an overload current flowing to the respective motors.

Overtravelof the machine elements is prevented by suitable limit switches included in the motor control circuits. These include (Fig. 8) switches IIB and ILS arranged to be opened respectively at the opposite limits of travel for the saddle I5, switches ILS land 2LS correspondingly associated with the housing I1 and swtches' 5LB and BLS cooperating with the ram I4.

' Srnmns Dnrvm Preliminary to starting'the spindle motor I0, the direction selector switch IID (Fig. 6) on the pendant 63 is set for either right or left hand rotation, as may be desired. For -the present it will be assumed that the switch IIO is set in its RH" position vas shown in Fig. 6. This preliminary setting of the switch IIU energizes the direction control relay FS (Fig. '7) thereby closing its contacts FSI in a circuit later to be completed for the run" relay RS and opening its interlock contacts FS2 which prevent simultaneous energization of the other direction relay BS. The contacts FS3 (Fig. 10) in the secondary control network are alsoclosed. It will be noted that the direction control relay FS (Fig. 7) is connected across supply lines Les-Lc, current being supplied to the latter supply line from the supply line Lv through normally closed contacts OLSI of the spindle overload relay. In the event of an overload on the spindle motor, these contacts OLSI will open "to drop out all of the relays supplied from the conductor Le. These include the secondary control relays for the B and C power pack feed motors (shown in Fig. 8) so that these motors will also be stopped simultaneously with the spindle motor in the event of an overload upon the latter.

As a further preliminary, current of proper potential is, of course, supplied to all of the sets of 4supply lines. ing windings LSN and |2SN of the time delair relays IIS and |2S (Fig. 10) are energized and furthermore, the main winding I2SM of the spindle accelerating contactor or relay |2S is energized through normally closed contacts |RS3, |FS3 and RSI while the main winding IISM of the relay IIS is energized through contacts IRSI and |FS3. Accordingly, the con' tacts |2S| and II'SI of the relays I2S and IIS (Fig. 11) open to insert all of the starting resistance |46 in series with the spindle motor armature IIS. Furthermore, the contacts IZSZ are closed to shunt out the field rheostat IZB so that the spindle motor will start onfull eld. In brief, the time delay relays IIS and IZS act to cut out the starting resistance |46 for the spindle motor circuit in two steps during starting and to insert thev field rheostat |28 in the circuit when the motor comes up to speed. The main and neutralizing windings of these relays are opposed. When the main winding is open-circuited, its magnetic iield decays and is overcome by the opposed neutralizing winding field after a time interval determined by the strength of the latter. This neutralizing neld strength may be varied at will by the setting of a shunt connected variable resistor, shown herein (Fig. 10) as a resistor, |52 for the winding IISN and |53 for I2SN. With the spindle motor circuits preliminarily conditioned as described above, the operator need only depress the spindle run push button II'IB (Figs. 6 and 7) momentarily in order to start vthe spindle motor I9. ASuch momentary closure of the switch |06 initiates a starting cycle for the spindle motor I9 inwhich it is started with full shunt iield and the starting resistance I46 in circuit and; after coming up to speed, the starting resistance is automatically cut .out and the speed adjusting rheostat |28 placed in series with the shunt field |20. In particular, closure of the run switch |06 momentarily energizes the control relay CRRf-(Fig. 7) which in turn energizes the running relay `RS through its contacts CRRI. The relay RS is maintained energized, however, through a sealing circuit in shunt with the contacts CRRI and including contacts RSZ, FSI and switch ||0.

Actuation of the running relays RS in turn completes an energizing circuit for the dynamic braking relay DBS (Fig. 10) through contacts I |S3, -|2S3, PLSI, and RS3. The dynamic braking relay DBS then opens its contacts DBSI (Fig. 11) `to open-circuit the dynamic braking As a result, the neutralizresistor |49 and closes its contacts DBSZ to complete energizing circuits for the direction control contactors IFS and 2FS. These latter contactors thereupon close their respective contacts IFSI and 2FSI (Fig. 11) to connect the spindle motor armature IIS across the supply lines Li-Ls for rotation of the spindle in the selected right hand direction. In this way, the spindle motor armature ||9 and series field |2I are connected across the supply lines for starting of the motor, and the shunt eld |20 is connected across the same supply lines through contacts RS4 of the running relay RS, which are in` shunt with the economy resistor |43.

The next step in the starting cycle is the dropping out of the rst time delay relay IIS due to the open-circuiting of its main winding IISM by opening of the contacts |FS3. When the relay IIS drops out, after a time interval determined as described above, it closes its contacts IISI (Fig. l1), to shunt out -part of the starting resistor |46, and also opens its contacts IIS2 to deenergize the main winding I2SM of the second time delay relay I2S (Fig. 10). After its selected time interval this latter relay therefore drops out, thereby closing its contacts I2S| 4to shunt out the remainder of the starting resistance and also opens its contacts |2S2 rheostat |28 (Fig. 11). Accordingly, the motor IQ is brought up to speed with all of the starting resistance nally cut out and the speed adjusting rheostat in circuit.

A starting cycle of the same character is used when the spindle direction selector I| is set in its LI-I position for left hand rotation of the spindle. 'Ihe only difference is that the selector switch II II thus energizes its other direction relay BS rather than the relay FS and, consequently the spindle motor main contactors IRS and 2RS (Fig. 10) are closed so that the spindle motor is connected to the supply lines Li-Ls (Fig. 11) through the contacts IRSI and ZRSI. The action of the other associated relays is the same in either case.

Speed changes for the spindle motor I9 may oe made while it is running by simply depressing the run button |06 and holding down the y, Similarly, if the run button |06 and the slower button I08 are simultaneously held down the relay contacts CRR2 will be closed and the other speed change relay |5CR (Fig. 7) will be energized and its contacts I SCRI closed (Fig. 10). In this way, the rheostat adjusting motor I3| is energized with its field |38 in circuit and the rheostat |28 is turned in a direction to decrease the speed of the spindle motor I9. In either case stoppage of the speed adjustment is effected by merely releasing the faster or slower button |01 or |08 so that its corresponding relay I4CR or I 5CR is deenergized and the rheostat adjusting motor I3I stopped.

To stop the spindle motor I9 the operator momentarily depresses the spindle jog button |09 (Fig. 6). This jog" push button energizes the jog relay JS (Fig. 7) so that its contacts JSI are opened to drop out the running relay RS. Deenergization of this latter relay in turn opencircuits the one of the sets of main contactors IFS-ZFS or IRS-ZRS, which has `previously been energized through its contacts RS3 (Fig. 10) so that the spindle motor is stopped. Opening of these same contacts R83 also deenergizes the dynamic braking relay DBS (Fig. 1'0) so that the relay contacts DBSI close (Fig. `l1) and connect the dynamic braking resistor |40 across the lspindle motor amature for dynamic braking of the spindle motor inthe usual manner. It should be noted here that contacts RS and R85 of the "run" relay RS are also included in the control circuits for the feed motors vof the B and C power packs (Fim 8) so that these latter feed motors can only be maintained in sustained operation when the spindle motor I9 is in operation or, in other words, when the spindle motor running relay RS is energized. Accordingiy, the jog" button |09 serves as a. safetystop device for stopping the entire machine in response to its momentary actuation. Desirably this jog button may be given a distinctive color so that it can be readily located by the operator in case of emergency. o

So-called plugging of the spindle motor I0 is prevented by the non-plugging relay PLS. As

.noted above its-"contacts PLS I are included in the initial circuit (Fig. for the two sets of main contactors IFS-ZFS and IRS- ZRS so that these contactors can only pick up when the relay PLS is deenergized or, in other words. when there is no voltage across the motor armature since the PLS relay is connected across the latter (Fig. 11). In' the event that the spindle motor is at rest when the starting cycle is initiated, the relay PLS will be deenergized and, hence, its contacts PLSI will be closed. Then, after the starting cycle has been initiated and one of the main contactors IFS or IRSpicked up, the latters centactsl S2 or IRS! complete a circuit (Fig. 10) for the corresponding set of contactors in shunt with the contacts PLSI. As a result, the subsequent opening of the contacts PLSI as the spindle motor comes up to speed.

' and hence energizes the relayPLS, will not drop out the main contactors. After the main contactors have been opened for stopping of the spindle motor, however, they cannot be reclosed until any voltage produced by the rotating spindle motor armature has died down so that the relay PLS is\deenergized and its contacts PLSI reclosed.

To adjust the' angular position of the spindle I3 itis sometimes desirable to turn the spindle at a slow jogging speed. For this .purpose the operator holds down the ."jog" button ill (Fig. 6. While the jog button is so held down the spindle motor I5 will turn the spindle at a slow jogging speed and stop as soon as the jog button isreleased. Closure of the jog button switch |05-'energizes the jog relay JS (Fig. 7) as previously noted so thatit opens its contacts JSI to drop out the running relay RS in the event that the spindle motor has been in operation and also to prevent the establishment of a self-maintained energizing circuit for the spindle motor. Additionally, the 4jog relay closes its energized to open-circuit the dynamic brakinl resistor and to pick up one or the other of the sets of main contactors IFS-ZFS or |RS-2RS (through contacts FS3 or BSB and DBS2, JSI, PLSI, i283 and |IS3). The spindle motor is thus started in the direction determined by the direction selector |10 and continues to rotate in such direction until the jog button |09 is released, thereby open-circuiting the jog relay JS which in turn opens its contacts JS2 to opencircuit the main contactors. During this motor operation a third set of contacts JS3 on the jog relay (Fig. 1-1) shunt the economyresistor |43. While jogging, the spindle motor I9 operates on full shunt eld since the contacts RSI. (Fig. 10) remain closed and hence retain the time delay winding IZSM energized so that the contacts |282 remain closed to keep the rheostat |20 shunted out of the neld circuit.

A Loox Connor.

All .of the clamping or locking mechanisms 55-61 for the column l1, saddle I5 and ram Il, respectively (Fig. l) are controlled from the singie lock" push button switch IIS on the pendant 63 (Fig. 6). To place this lock" button in control ot a desired one of the clamping mechanisms.

tion showniFigs. 6 and 7) the lockmpush button switch I|6 is in operative relation with the clamping mechanism 66 for the vertically movable saddle I5. Momentary closure of the lock" switch ||5 energizes its control relay |0CR. The selector relay ICR is already energized through the selector switch |05 and interlock contacts ICRI and ICRI, which prevent simultaneous closure of the other selector relays ICR and SCR. Accordingly, the main contactor VL for energizing the motor 69 for rotation in a direction to set the clamps, is energized through`relay contacts VOLI, 2CR3, |0CRI, the limit switch SLS, and interlock contacts VUI on the other main contactor for the motor 59 (Fig. 12). Energization of this contactor VL connects the motor v60 vto supply lines Li-La-I thr ugh contacts switch OLS', which drops out the main contactor VL and thereby deenergizes the motor 60. should be noted that even continued closure of they lock" switch IIB will not reenergize the motor 55 for further clamping so longl` as the limit-switch BLS is openp In the event of an overload, the overload relayVOL opens its contacts VQLI dropping out the contactor VL to stop the motor 09.

'I'he clamping operations for the -ram Il and 'horizontally traversable housing |1 are similar to that for the saddle I5 described above. In particular, when the selector switch |05 is set in its ram position the corresponding selector relay ICR is energized through the switch |05 and interlock contacts ZCRZ and SCR! (Fig. 7) so that I'of the clamping operation by opening of the limit its contacts ICR3 are closed (Fig. 12). Accordingly, energization of the lock relay |0CR, with the selector |05 in the ram position, closes its contacts |0CR2 to complete a circuit for the main contactor RL through these contacts as well as relay contacts ICR3, ROLI, limit switch 'ILS and interlock contacts RU4 (Fig. 12). 'I'he contactor RL in turn connects the ram clamping motor I0 to supply lines Li-La-La through its contacts RLI-RL3 (Fig. 13) the contactor RL being maintained energized through its sealing contacts RLS. Similarly, if the selector I 05 is in its horz position (Fig. 7) the corresponding selector relay 3CR is energized through the switch |05 and interlock contacts |CR2 and 2CRI. Consequently, the loclf relay I UCR may be energized to close its contacts |0CR3 and complete an energizing circuit for the contactor H1 (Fig. 12) through not only these contacts but also relay contacts 3CR3, HOLI, limit switch IIIS and interlock contacts HU4, the contactor remaining energized through its sealing contacts HL5. When this contactor HL picks up, the housing clamping motor 68 is energized from the supply lines through its contacts HL|-I-IL3. In each case the clamping motor 68 or I0 is stopped by the opening of its corresponding limit switch |ILS or. 1LS and in the event of overload will be stopped by opening of its overload relays contacts HOLI or ROLI.

To rotate the motors 68--10 in the opposite direction for unclamping operation, the other main contactors HU, VU and RU, respectively, are closed (Fig. 13) to connect the motors to the supply lines through the corresponding sets of contacts HUI-HUB, VUI-VU3 and RUI-RU3 (Fig. 13). Energization of these contactors is 4accomplished as an incident to the starting of the drive mechanisms for the respective machine tool elements as hereinafter described in connection with the operation of the controls for these drive mechanisms.

MAIN CONTROLS I 05, preliminary setting of `it in its vert posi-. tion shown in Fig. 6 energizes Athe selector relay.

2CR (Fig. 7) to close its contacts ZCRJ (Fig. 12)

and thereby energize thel solenoid SS so as to en-` gage the clutch 38 (Fig. 1) for connecting the B power pack to the vertically movable saddle I5. Similarly, setting of this selector |05 in its horz position energizes the selector relay 3CR (Fig. 7) again energizing the solenoid SS but this time through the contacts 3CRII (Fig. 12). Incidentally, it should be noted that when the selector I05 is in this horz position, the main controls are connected with the C power pack and the auxiliary lcontrols govern the B power pack which is connected to the saddle I5. Finally, when the selector |05 is in its ram position the selector relay ICR is energized and closes its contacts |CR4 (Fig. 12,)to energize the solenoid SR for engaging the clutch 33 (Fig. 1) to connect the B power pack in driving relation with the ram I4.

'I'he second or direction selector |I5 noted above is. of course, preliminarily positioned for the desired direction of movement of the element to be operated. When in its "up or forward position the relay 'ICR is energized and, correspondingly, when in its back or down position the relay BCR is energized (Fig. 7). As a result the corresponding secondary direction relay FB or BB (Fig. 8) is energized (assuming the element selector |05 is in its vert position as previously noted). In particular, the relay FB is energized in response to the energization of the primary relay 'ICR through the overload relay contacts OLBI, limit switch |0LSA, and relay contacts ICR5, ZCR'I, 'ICR|, limit switches 3LS and ILS, and interlock contacts BB2. Similarly, if the other direction relay BCR is energized it in turn energizes the alternative secondary direction relay BB (Fig. 8) through contacts OLBI, limit switches |0LSA, relay contacts ICR5, 2CRB, BCRI, limit switches 4LS and 2LS, and interlock contacts FB2. In general, the alternative direction relays FB and BB condition respective energizing circuits for the feed motor 2| for subsequent completion during the feed motor starting cycle described below.

In starting the drive for the machine element selected for control by the main group of controls, the operator simply pushes the run button III (Fig. 6) irrespective of-whether or not the selected element is clamped. If it is clamped, the actuation of the run button will cause it to be automatically unclamped before the drive starts. If it is not clamped, then the drive starts at once. It will first be assumed that the element selector |05 is set in its vert position to connect the B power pack to the saddle I5 and that the saddle is clamped on its ways by the clamping mechanism 66. In such case, the selector relays 2CR and 'ICR are, therefore, both energized (Fig. '7) and the intermediate direction selector relay FB is also energized as previously noted (Fig. 8). With the parts so arranged, to unclamp the saddle I5, the operator momentarily depresses the m-ain run push button I I l. Closure of this run button switch |I| energizes its control relay 4GB. (Fig. 7) so that the latters contacts 4CRI (Fig. 12) are momentarily closed to establish an .energizing circuit for the unclamping contactor VU (through contacts VOLI, 2CR5, 4CRI, limit switch IOLS and interlock contacts VIA) to energize-the motor 69 for unclamping movement. The contactor` VU remains energized through its sealing contacts VU5. The unclamping movement continues until at its termination the limit switch |0LS opens to drop out the vcontactor VU and, of course, -in the event of overload the contactor will be dropped out to stop the motor -69 by opening of the overload relay contacts VLOI.

In a similar manner, if the selector |05 is set in its ram or horz positions (Fig. 6), the corresponding selector relays ICR or 3CR are energized so that when the run button III is depressed and the run relay 4CR momentarily energized circuits will be completed correspondingly for the unclamping contactors RU or HU of Fig. 12 (through a circuit including contacts ROLI, |CRIO,-4CR2, limit switch BLS and interlock contacts RL4 for the contactor RU, and similarly through contacts HOLI, 3CR|6, 4CR3, |2LS and HL4 for the contactor HU). In each case, the circuits are sealed through sealing contacts RUS and HU5, respectvely, and are opened at the ends of the unclamping movements by limit switches SLS and IZLS, respectively.

After the unclamping operation for the selected element its feed motion is started by again momentarily depressing the main run button III. If desired, this "run button can be held down throughout the unclamping operation and for a sumcient time thereafter to start the feed.

Before proceeding to a description of the feed motor starting cycle vattention should be given, however, to the initialrcondition of certain of the relays which take part in the cycle, particularly the time delay relays IIB and IIC. These are associated respectively with the controls of the feed motors 2| and 49 in the B and C power packs. In general, they cause relays IAB and IAC to close their contacts and shunt out the starting resistors |41 and |48 (Fig. 11) of the' respective feed motors as thelatter come up to speed, and also d'eenergize the relays FAB and FAC to remove shunts from about the eld rheostats |29 and I 30. Thus, the motors are started with the starting resistors in circuit and on full shunt eld. The time delay relays are of the same general type as the relays IIS and I2S (Fig.

10) associated with the spindle motor I9 and.

previously described, although only one rather than two is used for each feed motor. In the case of the relays IIB and IIC the time delay interval for opening of the relay is regulated by variable resistors |54 and |55, respectively (Fig. 9). With the feed motors 2| and 49 in the B and C power packs, respectively, lstopped and voltage on the supply lines lie-Ls, both the main and neutralizing windings of the relays IIB and IIC are energized. The main windings IIBMV and IICM are connected across the supply lines through `sets of relay contacts IRBI, IFB2 and |RC|, IFCS, respectively. The relays IIB and IIC are thus conditioned to perform their timing operations during starting of the respective feed motors. Furthermore, the relays FAB and FAC are energized (through contacts HB2 and I IC2) so that their respective contacts FABI and FACI (Fig. 11) are closed to shunt 'out the feed motor rheostats. Similarly, the relays IAB and IAC are open-circuited by contacts IIB3 and IIC3 (Fig. 9) so that their contacts |AB2 and I AC2 are open (Fig. 11) and the starting resistors in circuit.

For Aan exemplary feed motor starting cycle, it will be assumed as before that the element selector is in its "ve "-position to connect the B power pack to the saddle I5 and to place this power pack under control of the .main controls.

Further, assume that the spindle motor I9 is running so that the interlock contacts RS5 and RSI, previously noted, are closed, and that the direction selector IIB is in its up position. In such case, a momentary closure of the run switch III energizes the run relay 4CR (Fig. 7) thereby momentarily closing its contacts 4CR4 (Fig. 8) to energize the running relay RB (through contacts OLBI, limit switch IOISA, contacts ICR5, SCRS, 4CR4 and JBI). Since the limit switch contacts IOISA are only closed when the saddle clamping mechanism 55 is in its unclamped position, it will be seen that the feed motor 2| 'is effectively interlocked against starting until the unclamping operation is complete. -The running 'elay RB maintains itself closed (through a sealing circuit including contacts OLBI, NLS-A, ICR5, 2CR1, 1CRI, limit switch 31S, contacts ZCRI, FBI, RS5, RBI, SCRS, and JBI). Closure of therunning relay contacts R132 (Fig. 9) picks up the relay DBB (through an initial circuit including contacts IIB-I, PLBI, IABI and 2RB2) which in turn energizes the main contactors IFB and ZFB (through an initial circuit including contacts IIBI, PLBI, IABI, RB2, DBBI and FBI).

The main contactors IFB- ZFB connect the feed motor armature |22 (Fig. 11) to the supply lines Li-Is through their contacts IFBI and ZFBI, the contactors being maintained closed through thesealing contacts 2FB2 (Fig. 9). Also.

'the main contactor IFB energizes the solenoid SB (Figs. 1 and 12) to release the saddle brake (through'contacts IFB2 and 2CR9). Additionally, the relay DBB opens its contacts DBB2 (Fig. 11) to out out the dynamic braking resistance |50 and the running relay RB closes its contacts RB3 tn shunt out the economy resistor |44. Consequently, the feed motor 2| starts in the selected direction of rotation with full shunt field excita.- tion and the starting resistor |41 in its armature circuit. If the direction selector switch ||5 is initially set in its other position, the starting operation is the same exc pt that the direction relays BCR and BB (rath r than 1CR andA FB) are energized with the result that the alternative set of main contactors IRB and 2RB are closed rather than IFB and 2FB.

Energization of the running relay RB also opens its contacts RBI (Fig. 9) deenergizing the time delay relay main winding IIBM so that after a selected time interval this relay closes its contacts IIBI to energize the starting resistor control relay IAB (Fig. 9). It in turn closes its contacts I ABZ (Fig. 11) to shunt out the starting resistor |41. Additionally, the time delay relay opens its contacts IIB2 (Fig. 9) to deenergize the relay FAB so that the latter contacts FABI (Fig. 11)` open and remove the shunt from about the speed adjustment rheostat |29. Accordingly, the feed motor 2| is brought up to speed with all of the starting resistance finally cut out of its armature |22 and the rheostat 29 inserted in the shunt field circuit.

Speed changes may be made for the feed motor 2| while it is running by simply depressing the run button III and holding down the faster or slower buttons |01 or |00 until the corresponding speed change is accomplished. Holding down the run button III retains its relay 4CR energized (Fig. 7) so that the latter contacts 4CR1 (Fig. 10) remain closed in the circuit of the rheostat adjusting motor |32. Accordingly, if the "faster button |01 is also held closed, its relay I4CR (Fig. '7) is energized and the latter contacts IICRI (Fig. vcomplete an energizing circuit for the motor |32 and its field |39 so that this motor rotates the rheostat |29 in a direction to increase the feed motor speed. Similarly, if the run button I I and the slower button |08 are simultaneously held down, the relay contacts 4CR1 and the other speed change relay |5CR (Fig. '7) willv be energized so that its contacts I5CRI are closed (Fig. 10). In this way, the rheostat adjusting motor |32 is energized with its eld |40 in circuit and the rheostat |29 is turned in a direction to decrease the speed of the feed motor 2|. It should be noted here that with the B power pack connected to the saddle I5, as assumed above, the rheostat motor circuit is completed through the selector relay contacts 2CR|0L65 If the B power pack is, however, connected to the ram, the rheostat motor circuit will be completed through the selector relay contacts ICRC.

On the other hand, if the B power pack is oper.

- To stop the feed motor 2|. it is only necessary momentarily to depress the main jog button ||2 (Fig. 6). 'I'his picks up the jog relay ICR (Fig. 7) which, in turn, energizes the secondary jog relay JB (Fig. 8) through its contacts BCRI and-the selector relay` contacts 2CRII, |CR5,

limit switch IOLSA and contacts OLBI. Thereupon, the contacts JBI in the circuit of the running relay RB are opened to drop out this relay so that the main set of contactors IFB- 2FB or |RB-2RB are opened (Fig. 9) and the feed motor 2| stopped. Notable here is the fact that if the spindle jog button |09 (Fig. 6) is momentarily depressed it similarly drops out the spindle running relay RS, as previously described so that the latters lcontacts R85 (Fig. 8) are opened and the B power pack running relay RB deenergizedto also stop the feed motor 2|. In

either case, when the feed motor 2| is stopped,

the relay DBB is dropped out (by opening of conresistor |49 (Fig. 1l) is connected across the motor armature by contacts DBB2.

The rates of acceleration and deceleration of the feed motor 2| are limited to safe values by the usual accelerating and decelerating relays FAB and FDB, respectively. Upon too rapid acceleration relay FAB closes its contacts FABI (Fig. 11) to shunt out Athe rheostat |29 and place full shunt iield on the motor. As soon as the rate of acceleration drops back to a safe value, the contacts FABI reopen without affecting the setting of the speed controlling rheostat. In the event of too rapid deceleration, the relay FDB swings its contact FDBI from the position of Fig. 11 to the left thereby substituting a resistor |56 in the shunt field circuit for the rheostat |29 to cut down the shunt field excitation and thereby diminish the rate of deceleration. It may be noted here that the same arrangement is provided for the feed motor 49 in the C power pack including accelerating and decelerating relays FAC and FDB. Contacts FACI of the accelerating relay shunt the rheostat |30 and contacts FDCI substitute the xed resistor |51- for the rheostat. To prevent plugging of the feed motors 2| and 49 in the respective B and C power packs, nonplugging relays PLB and PLC are utilized (Fig.

11). These relays operate in substantially the same manner as non-plugging relay`PLS for the 50 spindle motor described above. In each case they are provided with contacts PLBI and PLCI (Fig.

9) included in the initial circuitsfor the main contactors (IFB-ZFB and I RB-2RB in one case and IFC-ZFC and IRC-2RC in the other) so as to prevent energization of these contactors until the feed motor armature has come to rest.

In order to jog the feed motor 2| with the selectors |05 and ||5 set as previously assumed, the operator need only hold down the jog button H2 (Fig. 6). While the jog button is held down the feed motor 2| operates at a low jog speed and stops as soon as the jog button is released. Closure of the jog button switch ||2 energizes the primary jog relay SCR (Fig. '7) as previously noted so that it picks up the secondary jog relay JB (Fig. 8) which in turn drops out the running relay RB in the event that the feed motor is in operation at the time and in any event prevents establishment of a self-maintained energizing circuit for the feed motor. Additionally, the relay JB closes its contacts JB2 (Fig. 9) so that one or the other of the sets of main contactors IFB-2FB or |RB-2RB (depending upon the setting of the direction selector 75 H5) are energized to start the feed motor in the tacts RB2 in Fig. 9) so that the dynamic braking manner previously described. I'he feed motor continues operating under the controll of the jog button until the latter is released, at which time both the primary and secondary'jog relays BCR and JB drop out and the main contactors are opened to stop the motor. During this motor operation, a third set of contacts JB3 (Fig. 11) on the secondary jog relay (Fig. 11) shunt the economy resistor |44. While J`ogging,.the feed motor 2| operates on full shunt field and, hence, at low speed, since the contacts JB4 (Fig. 9) retain the time delay relay ||B energized so that the relay FAB is energized and its contacts FABI closed to shunt the rheostat |29 (Fig. 11).

For rapid traversing of the saddle I5 with the selectors set as previously assumed, the operator holds down the traverse" button H3 (Fig. 6) throughout the desired rapid traversing movement. Closure of this traverse switch ||3 picks up the associated primary relay SCR (Fig. 7) thereby closing its contacts SCRI (Fig. 12). This in turn completes a circuit for the B power pack traverse motor contactor RAB (through contacts SCRI, OLRBI, 2CRI2, FB4, and interlock contacts RRBI). Energization of this contactor RAB connects the rapid traverse motor 22 to supply lines Li-La-Ls through its contacts RABl--RAS (Fig. 13). Accordingly, the rapid traverse motor is started and continues in operation until the traverse push button I3 is released to drop out its relay SCR and the contactor RAB. It will be clear that if the direction selector H5 is set for down movement, the direcaen relay contacts B134 (Fig. 12) win be closed rather than the contacts FBI so that the other main traverse contactor RRB will be energized and close its contacts RRBI-RRB3 to connect the traverse motor 22 for rotation in the opposite direction. Similarly, if the element selector |05 is set in its ram position, one or the other of the rapid traverse contactors RAB or RRB is energized through the corresponding selector contacts |CR1 rather than 2CRI2. 'I'he machine tool element which is operating under the main group of controls can thus very readily be operated at a rapid traversing speed whenever desired as, for example, in approaching the tool to the work piece.

Rapid traversing may be initiated either when the associated feed motor is running or is stopped. The circuits, set forth above, for the rapid traverse contactors RAB and RRB are independent of the feed motor controls and can therefore be completed whether or not the feed motor is running. Additional contacts RAB5 and RRB5 (Fig. 12) on these contactors insure energization of the brake solenoid SB when the rapid traverse motors are running alone. In the event the feed motor is also running, release of the traverse button I| 3 stops the rapid traverse motor as noted but leaves the feed motor running so that the driven machine tool element drops back to its previous slow feed speed.

In some machining operations, it is desirable to move the machine tool element, governed by the main group of controls, at a so-called fast feed speed or, in other Words, at a speed intermediate the usual feed speed range and the much faster rapid traversing speed. This operation is particularly useful when a light cut is to be made so that the work and tool can be moved relative to each other at a speed substantially in excess of that for a heavy cut. If the selectors are set in the manner previously assumed, then the operator can run the feed motor 2| at a fast feed rate by simply holding down `the fast feed button I-II (Fig. 6). 'Ihis push button III picks up its primary relay SCR (Fig. 7) which in turn picks up the secondary fast feed relay FFB (Fig. 8), energizing the same through contacts OLBI, IOLSA, ICR5, 2CRI I, and SCRI. This relay FFB in turn opens its contacts FFBI (Fig. 9) to open a shunt normally placed about a resistor |58 in the energizing circuit of the potential winding of the relay FDB. As a result, the energization ,of this winding is diminished so that the relay FDB swings its contact FDBI (Fig. 11) to shunt the rheostat |29 by the fixed resistor |56. Consequently, the shunt eld excitation of the feed motor 2l is reduced and it operates at a fast feed speed. As soon as the fast feed button IIA is releasesi, the relays OCR, FFB, and FDB drop out and the feed motor speed drops back to the value determined by the previous setting determined by the rheostat |29. Notable here is the fact that the decelerating relay FDB performs Vnot only its decelerating control function but also the additional function of controlling the shunt'fleld-excitation for the feed motor during fast feed operation through the use of the shunted resistor, in its potential winding circuit. 'I'he relay FDC in the C power vpacliz control circuit is provided with a similar resistor |59 controlled by contacts FFC-I for the same 'purpose in the control of the C power pack eld motor 40.

In the event that the element selector |05 (F1a. 6) is initially set in its ram position, rather than its vert" position as assumed above, the "main group of controls are connected to the B power pack, but this power pack is connected to the ram Il rather than to the saddle I5. The feed and rapid traverse motors 'of the B power pack can, of course, be controlled in the same manner for feeding, fast feeding, rapid traversing and Jogging of the ram just as was the case with the movement of the saddle described above. On the other hand, if the element selector |05 is turned to its horz position, the main group of controls are connected inoperative relation with the C power pack which traverses the horimntally movable housing I1. The C power pack,

as previously noted, also includes feed and rapid` `traverse motors and the control circuits for these two motors substantially duplicate those for the corresponding motors of the B power pack. Corresponding reference numerals have been used to identify the controls `oi.' the C power pack except that tlre distinguishing letter "C is used instead of the letter ,B as in the case of those for the B power pack. 'Ihe operation or these controlsfor the C power pack, under the "main" group of manual switches, exactly matches that for the B power packl and, accordingly, a further detailed description of them is believed to be unnecessary.

When any one of the movable machine tool elements, viz., the ram I4, saddle I5, or the column |1, is being driven, its associated limit switches previously noted prevent overtravel. 1n the case of the ram Il, its limit switches 5LB and BLS (Fig. 8) are arranged to drop out correspondinffv ones of the secondary direction relays FC and BC so as to stop the C power pack although leaving the same conditioned for' movement in the opposite direction. Similarly, the saddle I5 will be stopped by one of its limit switches 3LS-4LS while the `ram'will be stopped by one of its limit switches ILS-ZLS in the event of overtravel. It should be noted as to these twoflatter sets of limit switches, however,

that they are in each case connected in shunt to contacts on the element selector relays ICR and ICR in such manner that-if, say, the saddle I5 has been stopped by one of its linut switches and in one of its limit positions by one of the overtravel prevention switches, the selector |05 can be turned to its "vert position and thevsaddle moved -by the `B power pack without changing the direction selector. 'I'his adds greatly to the flexibility of the controls without in any way im' pairing the safety of operation.

Whenever thecolumn I1 is being traversed, lubricant is desirably supplied to the drive gear 56 (Fig. l). vA pump (not shown) driven by the motor 62 (Fig. 13) serves this purpose. During jogging or intermittent driving of the housing. excessive starting and stopping of the pump motor would be incurred if it were merely started and stopped in synchronism with the C power pack. Accordingly, the time delay relay TD (Fig. 8) is utilized to give a period of overlap or continued operation of the' pump motor after the C power pack is stopped so that if the latter is restarted within the time delay period, the pump motor will merely continue to operate without interruption. Whenever either the feed motor 40 or rapid'traverse motor 50 of the C power pack are started, the pump motor contactor LP (Fig. 8)

is energized (through contacts OLCI, OLPI,

TDI, and any one of the following motor reversing contactors which happens to be closed for the particular operation, viz., IHM, IRC4, RACE,

RRCG). Thereafter, the'contactor LP is maintained energized through its sealing contacts LPI and connects the pump motor 02 to supply lines Li-La-Io (Fig. 3) throughits contacts LPZ-l- LP4. During the time that the C power pack is running, the time delay relay TD (Fig. 8) is retained deenergized. however, by the opening of one of -the series of contacts IFCl, IRC, RAC1, and RRC1. Then, when the power pack C is stopped, the time delay relay TD is energized through closure of one of the last named series of contacts and the pump motor contactor LP remains energized through its sealing contacts LPI. Finally, after a predetermined time interval, the,

relayTD opens its contacts TDI to dropout the contactor LP and also to deenergize the time delay relay itself. The resultant reclosure of the contacts T DI returns the circuit to its initial con- Thus, if the power pack C is're'started after only a short interval, there will be no interruption in the pump motor operation.

-AUxILrAaY Commons' "dition but leaves the contactor LP deenergized.

column I1. Similarly, when the "main" controls are connected to govern the column drive, the "auxiliary controls are automatically connected to govern the B power pack and, furthermore, the latter is connected to the saddle I5.

In brief, the auxiliary controls'serve to perform the followingicontrolling functions for the feed motor power pack to which they are connected, viz., stop, start, change direction, and change feed speed. Although less elaborate than the category of control operations accomplished by the main controls, this is sumcient for many operations, particularly proling, in which two of the machine elements are moved simultaneously to produce a resultant cutter movement inclined relative to the ways of the machine elements.

Assuming that the spindle motor it is running and that the element selector 05 (Fig. 6) is st in its horz position, the auxiliary controls will be eiectually connected to the B power pack (through circuits established by the selector relay BCR of Fig. 7 which is energized by the selector switch Furthermore, the solenoid SS (Fig. 12) is energized through contacts 3CR4 to engage the clutch 38 (Fig. 1) to connect the saddle l5 to this B power pack. Accordingly, the operator sets the auxiliary direction selector M8 (Fig. 6) for the desired direction of saddle movement which energizes either the primary direction relay HCR. or MCR (Fig. 7) depending upon the direction selected. When the' relay HCR is energized, it closes its contact MCRE (Fig. 8) to energize the secondary direction relay FB (through contacts OLBU, iiLSA, lCR, SCRS, llCRi, SLS, -iLS). Similarly, ii the other primary relay IZCR, is energized, it closes its contacts I 2CRI to energize the other secondary direction relay BB (through contacts OLBl, lIJLSA, HCRS, 3CR9, IZCR, (im, 21S). Then, to start the B power pack feed motor 2i, the operator holds down the prole" button lil (Fig. 7). This switch energizes the prole relay I 3CR so that it closes its contacts @CB2 (Fig. 8) for energization of the running relay RB (through contacts OLBI, ZCRM, CR, tCR, MCRI, SLS, IIS, FBl, I3CR2, 3CRW, and ii. It should be noted here that the contacts SCR@ and SCRS are open so that no maintaining circuit is established for the running relay RB. As a result, this relay will drop out again and stop the feed motor as soon as the prole button lil is released. Establishment of the g relay circuit described above causes it to start the feed motor 2l by the starting cycle previously described in connection with the main controls. The proflle button can be held depressed by the latch l il (Fig. 6) for sustained operation.

To change the speed of the feed motor ,2i while it is operating under the auxiliary set of controls, the profile button Ill is held depressed and one or the other of the faster or slower buttons I 01 and |08 is depressed until the desired speed change is effected. The speedchanging operation is substantially the same as that described with respect to the main" controls above in that the rheostat adjusting motor 35 (Fig. 10) is energized with the desired adjustment of the speed controllingl rheostat. In this case, however, the circuit is completed through contacts of the profile relay |3CR rather than through contacts 4CR5 of the main control run relay.

When the element selector I 05 (Fig. 6) is set in its vert or ram positions, the corresponding relays ICR and ZCR cause the auxiliary" set of controls to be connected to the C power pack. In such case, the same controlling operations can be carried out and in the same manner as those for the B power pack described above. The controls for the C power pack contain elements which are counterparts of the B power wpack control system set forth and, accordingly,

a further detailed description is believed unnecessary.

BRIEF BESUM or OPERATION In starting the machine, power is furnished to all of the various sets of supply lines and the time delay relays HS, 82S, IIB and IIC are consequently all energized in preparation for the control of the starting cycles of their associated motors. pack is ordinarily started first, since safety interlocks prevent regular sustained operation of the B and C power pack feed motors except when the spindle motor is running.

Preliminary to starting the spindle motor i9. its direction selector il@ (Fig. 6) is set for the desired direction of spindle rotation. Then, to start the spindle motor i9, its run button it@ is depressed momentarily and thereafter the inotor starting cycle is automatically carried out. To stop the spindle motor, the jog button H93 may be momentarily depressed or the selector il@ shifted to its other position. The speed of rotation may be increased or decreased by holding down the run button it so as to connect Y the faster and slower buttons till-M38 with the rheostat adjusting motor H3G and then holding down either the faster or slower button until the desired speed change is accomplished. Jogging of the spindle motor is eected by holding down the jog button m9.

To clamp in position any one of the several movable machine tool elements, viz: the ram ifi, saddle l5, .and housing il, the vselector 05 is turned to the corresponding position, and then, the lock button il@ momentarily depressed. Unclamping of the element takes place automatically when starting its drive mechanism.

For full control of the operation of a desired one of the machine tool elements, the selector m5 is turned to the corresponding position so as to connect the main set of controls to the drive mechanism for the selected element. This selector also automatically connects the B power pack to either the ram Mi or saddle I5, depending upon the setting of the selector, and in the event the main controls are connected to the C power pack, for the Icolumn il, the B power pack is connected to the saddle l5. Preliminary to starting the drive mechanism which is connected to the main set of controls, the direction selector H5 is set for the desired direction of movement. The feed motor in the selected power pack is then started by momentarily depressing th run button iii and may be stopped by momentarily depressing the jog button M2 or by shifting the direction selector H5. Jogging, rapid traversing and fast feeding operations may each be obtained by holding down the corresponding one of the hold-down buttons SI2-H5. The feed speed may be changed by holding down the run button HI and depressing one or the other of the faster or slower buttons lill, Mld. i

For proling and similar machining operations in which two of the machine elements must be fed simultaneously, the power pack which is not The spindle motor i9 of the A power' 

